Trouble

So my boyfriend woke up from a nightmare and I was there to help him. Next thing I know, a girl named Jackie, messages him.
She messaged him this, "Hey sexy remember me."
Now, of course, that pissed me the hell off, heck I am still mad. But honestly, it's fucking stupid, that the hoes try to get with a man who is with someone. I don't understand why they do this. But it's bullshit. I have been through a lot, but this makes it where my depression comes up and makes it where I am very possessive of my boyfriend, and also to slap the fucking ho.
Look, I don't care if your white, black, purple, red, etc. It is fucking wrong to mess with a guy or chick who is taken. And on my boyfriend's facebook account it clearly states that he is in a relationship with me. IF you see that and yet still message the person, you're asking to get a beat down.
But now it keeps running throw my mind, what if he wants someone better? what if when he sees me, he will hate me? All these questions keep running through my mind. It makes my depression go up. When that happens, I won't go out of the house, won't talk much, but I will still beat the shit out of someone who flirts with my boyfriend.